As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
One type of information handling system is a modular server, such as a blade server or simply “blade.” A modular server may include any number of self-contained information handling systems configured to be placed in a single enclosure, or chassis. A modular server chassis may hold multiple servers (e.g., blades) and provide services to the various servers such as power, cooling, networking, interconnects, and management. For example, the chassis may include a plurality of power supply units (PSUs) configured to provide power to blades mounted in the chassis.
A modular server chassis may include a chassis manager, e.g., a chassis management controller (CMC), configured to provide local and/or remote management of various chassis functions. Some modular server chassis include redundant chassis managers such when an active manager fails, the system may automatically fail over to a standby manager, which then becomes the active manager.
Power management is an increasingly important issue regarding modular servers. Most network switch appliances and modular server system I/O modules allow user-defined control of various network configurations on a per port basis. These configurations are typically static in nature, require administrative control, are typically used for security purposes, and/or do not include power down of physical links (PHYs).
Modern modular servers typically have an internal chassis network for management type communication between modules. These links often are utilized under standby power and significantly add to the standby power requirements that customers desire to reduce.
Some modular servers have a number (e.g., 50) of internal management Ethernet links that contribute to the standby and main power draws. In addition, the proliferation of integrated networking into embedded systems on a chip (which are functions such as BMC, IDRAC, etc.) are promoting the use of management Ethernet links in monolithic servers as well. It is common in physical layer communication devices such as Ethernet PHYs and switches that the analog portion of the chip driving the physical link are a large percentage of the chips' overall power draw.
Current products typically leave all networking physical interfaces (Ethernet PHYs, transmitters and receivers) statically powered on and able to link, although passing traffic is typically under chassis manager or user control. Thus, there is a lot of wasted power by leaving transmitters on, for example, when (a) a module has no link partner, (b) a module is not capable of management traffic, (c) a module is not currently powered on, and/or (d) there is no active management traffic.
In addition, out-of-band interfaces (e.g., GPIOs, Time Division Multiplexed Shifty or I2C I/O expanders) exist in parallel to the management links. In some systems, management traffic is typically pushed from the chassis controller (it knows when out-of-bound traffic is required), and when a module has a traffic generating event, it asserts an out-of-band alert for the chassis manager to query via the management fabric to identify the event.
Independent of link status in a modular system, a chassis manager typically has knowledge of the chassis state, current mode of operation, module presence, module power state, and whether particular modules support particular management network interfaces.